The recoil distance transient field technique in coincidence mode has been used to measure the magnetic moments of the ${21/2}^{+}$ and ${29/2}^{-}$ yrast states in ${}^{87}\mathrm{Nb}$. This method in conjunction with the use of five highly efficient EUROBALL cluster detectors has for the first time allowed the direct determination of individual $g$ factors of picosecond high-spin states populated in heavy-ion compound-nucleus reactions. The value $g\left({29/2}^{-}\right)=+0.56\mathrm{}\left(16\right)$ indicates that the five-quasiparticle band consists of both an aligned $g_{9/2}$ proton and a $g_{9/2}$ neutron pair besides the odd $p_{1/2}$ proton.

• Received 6 October 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.2793